Thousands of people die each year because of heart related problems, including heart disease, heart attack (myocardial infarction), stroke, and heart failure. In many cases, significant heart problems may be corrected through medication, transplant, stenting, valve replacement, medical consultation, or other forms of medical intervention. Medical personnel need an effective method of monitoring the patient's heart for different symptoms, conditions, and parameters in order to provide effective treatment.
For the most part, heart monitoring requires that the patient visit the physician for an electrocardiogram (ECG) and/or other diagnostic tests. Frequently, the ECG by itself is only one of the many diagnostic tools that the physician has in his/her armamentarium, and not adequate alone to diagnose transplant rejection, heart failure, and other heart related disorders.
Current heart monitoring systems provide limited heart monitoring capabilities. Other systems are ineffective at detecting problems because of patient movement, respiration, inspiration, and emotional or physiologic stress. Frequently, traditional methods of heart monitoring are ineffective or incapable of detecting the subtle heart performance metrics that may indicate that heart failure or transplant rejection is present or imminent.
When cardiac events occur infrequently (paroxysmal occurrences), EGG may not be effective in detecting certain heart events, such as arrhythmias, tachycardia (fast than normal heart rate), bradycardia (slower than normal heart rate), premature ventricular contractions (PVC), bigeminy, trigeminy, or other abnormal rhythms.
In many dire situations, a heart transplant is the only option for the patient. For these patients, who are placed on anti-rejection medications, anti-inflammatory medication, and any host of other medications, assessment of transplant rejection is of paramount importance. In order to assess rejection, patients require frequent endomyocardial biopsies (EMB).
An EMB is the process of removing tissue from living patients for microscopic diagnostic examination. An EMB requires that small pieces of heart tissue be removed and examined under a microscope. To get the sample of heart tissue, a doctor places a small catheter or tube into a large vein in the neck or a large artery in the groin, which is then passed into the heart. Tiny pieces of the heart tissue are removed and sent to the lab where they are microscopically examined. Biopsies may also be performed if the doctor suspects a heart related disease not related to transplant, or if the heart is not pumping well for unknown reasons.
Biopsies are invasive, painful and frequently leave large scars. In most cases, heart patients dread the thought of a biopsy which adds to post-operative stress and surgical dissatisfaction. The EMB routine for transplant patients varies from 13 to 22 EMBs in the first year following transplant. This form of transplant monitoring for rejection is the standard of care today, and may be difficult, time consuming, expensive, and painful. A small percentage of yearly EMBs result in patient death. As a result, heart monitoring is still plagued by many difficulties and complications despite the many improved techniques and technologies available in modern medicine.